There was the recent abortion clinic shootup and the dude that flew his plane into the IRS building in Austin after 911, but they are far and few between despite what the forked tongued serpents of the media hiss.
I wouldn’t necessarily call those acts of terrorism. The “abortion clinic” shooter was just a crazy shooter, who happened to be outside an abortuary. The press tried to puff it all up, but, seriously, had the same incident happened outside of a dental clinic, it might not have been news outside of the local area at all. The guy flying his plane into the IRS building had some serious issues; whether what he did was an act of terrorism is debatable.